Squeeze molding machine



Nov. 30, 1965 E. K. HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28. 1961 8 Sheets-Sheet 1 INVENTOR.EDMOND K. HATCH a BY LEON F. MILLER mlmuhuqlflomdlu ATTORNEYS Nov. 30,1965 E. K. HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet 2 I45 4 A- Il4 G54 -FQ L :H' uo ua F I0 Nu T Q l I F1 4 E1 y: i

" R I. INVENTOR- EDMOND K. HATCH a :29 By LEON E MILLER ATTORNEYS Nov.30, 1965 E. K. HATCH ETAL SQUEEZE MOLDING MACHINE 8 Sheets-Sheet 5 FiledJuly 28, 1961 I33 A s \W g ms 4 INVENTOR.

EDMOND K. HATCH 8 BY LEON F. MILLER Obaiin. milky 4L flomulg ATTORNEYSNov. 30, 1965 E. K. HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet 4 O O O 0 O OO O O g o O O O 0 O 0 0 FIG 5 o E 6 -|6O I63 0 U o g 0 O 0 I74 FIG 6 I73I I69 3 I79 //////I I 2 W I78 -I67- I76 FIG 7 INVENTOR.

EDMOND K. HATCH 8 LEON F. MILLER oherlmmamllmlly ATTORNEYS Nov. 30, 1965E. K, HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28. 1961 8 Sheets-Sheet 5 HVVENTDR.EDMOND K. HATCH a BY LEON F. MILLER -"WWW ATTIXUVEYS Nov. 30, 1965 E. K.HATCH ETAL 3,220,065

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet 6 IN V ENTOR.

EDMOND K. HATCH a FIG 9 BY LEON F. MILLER ATTORNEYi Nov. 30, 1965 E. K.HATCH ETAL 3,220,056

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet '7 INVENTOR.EDMOND K. HATCH a BY LEON F MILLER FIGIO OMMMWMM ATTORNEYS Nov. 30, 1965E. K. HATCH ETAL 3,220,066

SQUEE'ZE MOLDING MACHINE Filed July 28. 1961 8 Sheets-Sheet 8 A329INVENTOR.

EDMOND K. HATCH a 330 By LEON F. MILLER ATTORNEYS United States Patent3,220,066 SQUEEZE MOLDING MACHINE Edmond K. Hatch, Brecksviile, and LeonF. Miller, Rocky River, Ghio, assiguors to The Osborn ManufacturingCompany, Cleveland, Ohio, a corporation of Ohio Filed .luly 28, 1961,Ser. No. 127,616 Claims. (Cl. 22-41) This invention relates generally,as indicated, to a squeeze molding machine and more particularly to afoundry molding machine adapted to produce foundry molds of uniformdesired hardness quickly and automatically.

Relatively thin flexible diaphragms have heretofore been employed infoundry molding machines to provide a uniform squeeze pressure on thetop surface of a sand mold within a flask. However, at the extremelyhigh squeezing pressures necessary to obtain molds of the proper uniformhardness, such diaphragms frequently rupture necessitating thereplacement of the entire squeeze head. This results in considerabledown time for the molding machine and where an entire molding system isinvolved, the loss of time and money is substantial.

It is accordingly a principal object of the present invention to providea simplified machine which will quickly and rapidly produce sand foundrymolds of uniform hardness.

It is another main object to provide a foundry molding machine utilizinga shuttle type head wherein the head may be shifted into and out ofoperative position to facilitate the direct overhead gravity filling offoundry flasks within the machine.

It is a further important object to provide a squeeze head for suchfoundry molding machine which is accessible and easy to replace andwhich will provide a uniform squeezing pressure over the entire surfaceof the sand mold.

It is a still further object to provide such squeezing head which willexert a variable uniform squeezing pressure on the sand mold and yetwhich will be extremely durable during operation of the machinerequiring less downtime for repairs and squeeze head changes.

Other objects and advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features herein after fully described andparticularly pointed out in the claims, the following description andthe annexed drawings setting forth in detail certain illustrativeembodiments of the invention, these being indicative, however, of but afew of the various ways in which the principle of the invention may beemployed.

In said annexed drawings:

FIG. 1 is a front elevation of a machine in accordance with the presentinvention employing a unique diaphragm squeeze head;

FIG. 2 is a side elevation of such machine as seen from the right inFIG. 1;

FIG. 3 is a top plan view of the machine of FIG. 1 on a somewhatenlarged scale;

FIG. 4 is a horizontal section taken substantially on the line 4-4 ofFIG. 2 illustrating the flask latching mechanisms;

FIG. 5 is a top plan view of the diaphragm squeeze head employed in themachine of FIG. 1;

FIG. 6 is a longitudinal vertical section of such squeeze head takensubstantially on the line 66 of FIG. 5;

FIG. 7 is a transverse vertical section of such squeeze head takensubstantially on the line 77 of FIG. 6;

FIG. 8 is a schematic piping diagram of the hydraulic and pneumaticcontrols of the machine of FIG. 1;

FIG. 9 is a front elevation of a further embodiment of the presentinvention utilizing a multiple piston squeeze head;

FIG. 10 is an end elevation of the machine of FIG. 9 as seen from theright thereof;

FIG. 11 is an enlarged vertical section of a squeeze piston-cylinder inaccordance with the present invention;

FIG. 12 is a similar vertical section on a smaller scale of a slightlymodified form of squeeze piston and cylinder; and

FIG. 13 is a schematic piping diagram illustrating the manner ofmanifolding and pressurizing such pistoncylinder assemblies.

Referring now to the annexed drawings and more particularly to themachine shown in FIGS. 1 and 2, it will be seen that such machine ismounted on the floor 1 by means of nut and bolt assemblies 2 and 3extending through flanges 4 at the corners of the triangular base 5.Transverse frame members 7 and 8 support vertically extending legs 9,10, 11 and 12. Secured between the top inside of the legs 9 and 12 is aframe plate 13 and similarly a frame plate 14 is secured between the topinsides of the legs 10 and 11. Both of these plates are provided witharcuate openings 15 therein as seen more clearly in the end elevation ofFIG. 2. Subadjacent the transverse frame members 13 and 14, there isprovided two longitudinally extending frame members 17 and 18 extendingbetween the pairs of legs 9, 10 and 11, 12, the member 17 being shownbroken away in FIG. 1.

A sand hopper 20 is mounted on top of the machine within a top box framecomposed of the members 21, 22, 23 and 24 (note also FIG. 3) with suchframe being mounted on relatively short legs 25, 26, 27 and 28, suchshort legs being provided with bottom flanges or bed plates which arebolted directly to top plates mounted on the legs 9, 10, 11 and 12 asshown at 30. The hopper 20 is secured to the frame members 24 and 22 bymeans of brackets 31, 32, 33 and 34. A pair of cutoff slides 35 and 36are supported for horizontal reciprocation on parallel rows of rollers37 and 38 mounted respectively on roller supporting bars 39 and 40secured to the legs 28, 27 and 25, 26 as seen in FIG. 3. Each of theplates 35 and 36 are provided with elevated side flanges 42 and 4-3 asseen in FIG. 2 which enclose the rollers 37 and 38 so that the plates 35and 36 are employed in cooperation with the flanges to provide groovesin which the rollers fit. A center sand distributing ridge 44 isprovided in the hopper and as seen the plates 35 and 36 extend beneathsuch ridge in the closed position shown. Such plates are actuated formovement by respective piston-cyclinder assemblies 45 and 46 which aremounted on pairs of brackets 47 and 48 on the top frame members 24 and22 respectively. The rods 49 and 50 of such piston-cylinder assembliesare connected to the cutoff plates 35 and 36 as shown at 51 and S2.

The sand measuring box 66 is positioned sub-adjacent the cutoff slideplates 35 and 36 on brackets 61 and 62 secured to the tops of the frameplates 13 and 14 respectively. Telescoped over the bottom of themeasuring box is a louvered opening assembly 63 mounted on pairs ofadjusting screws 64 and 65 mounted on the plates 13 and 14 respectively.Pairs of brackets 66 and 67 are employed to support the assembly throughthe adjusting screws 64 and 65. The brackets 67 additionally support apiston-cylinder assembly 68, the rod 69 of which is connected to alouver actuating bar 70. This bar pivots louvers 71 which are in turnpivoted to the frame of the assembly 63 to open and close the bottom ofthe sand measuring box 69. It can now be seen that by adjustment of thescrews 64 and 65, the depth of the box or the distance of the louversfrom the cutoff plates can closely be controlled thus to increase ordecrease the amount of said within the measuring box 60.

Mounted on the legs 9, 1t}, 11. and 12 beneath the louver opening frameassembly 63, there is provided a carriage supporting frame 81} whichincludes two elongated side frame members 81 and 82 supporting inwardlydirected row of rollers 83 and 84. The carriage supporting frame 80includes a transversely extending end frame member 35 and an oppositecylindrical end frame member 86 on which is mounted a piston-cylinderassembly 37 by means of brackets 88. The rod 89 of such pistoncylinderassembly is connected as shown at 96 to the carriage frame 91 of squeezehead 92. The rod 89 is covered by a shield 93 so that when in itsextended position it will not be exposed to loose sand falling from themeasuring box 60 and the louver assembly 63. The shield 93 is preferablymounted on the carriage frame 91 for movement therewith and thus withthe rod 89. The carriage 91 is provided with a top plate 94, the sidemarginal edges of which overlie the inwardly directed rows of rollers 83and 84. Such marginal edges also underlie the frame members 17 and 18(see FIG. 2) when the squeeze head 92 is in the operative squeezingposition shown in FIG. 1 to provide a firm top backstop for the squeezehead.

A sand filling chute fit? is similarly mounted on a plate 97 having acentral aperture therein and the chute carriage is connected to thesqueeze head carriage by links 98. Thus the piston-cylinder assembly 87is effective horizontally to reciprocate both the squeeze head and thefilling chute. Such filling chute includes a flared top portion '99which receives the sand from the opened louvers 75 and deposits itthrough the discharge opening 101) in the bottom thereof. A strike-offblade 161 is secured to the bottom edge of the chute to strike oh theexcess sand on the flask as the chute is moved from the filling positionto the position shown in FIG. 1.

The flask F shown in phantom lines is, of course, conventional and issupported on its bottom flange by conveyor rollers 111 inwardly directedfrom conveyor roller supporting bars 112 and 113. These bars may bebolted or otherwise suitably secured directly to the legs 9 through 12of the machine frame. Mounted on each bar 112 and 113 are a pair ofpneumatic cylinders 114 and 115, the rods of which are connected asshown at .116 and 117 respectively to fill frame 118. As seen in FIG. 2,the fill frame 118 is provided with a depressed center portion in theside walls 119 and 120 thereof to accommodate the strike-ofl blade 191.The piston-cylinder assemblies 114 and 115 act as air springs tomaintain the fill frame in its lowermost position resiliently to beraised by the elevation of the table T which will lift the flask F offthe rollers 110 to engage and lift the fill frame 118 against thepressure of the air cylinders 114 and 115 to cause the thus formed moldbox composed of the fill frame, flask and table to move upwardly againstthe squeeze head 2. It is noted that the fill frame 118 and accordinglythe flask F are dimensioned peripherally to telescope over the outsideof the marginal peripheral dimension of the squeeze head. There will bea very slight peripheral clearance between the fill frame and flask andthe marginal portions of the squeeze head 92 as shown by the phantomline position of the flask and fill frame at 121 in FIG. 1. If desired,a brush or like sliding seal may be incorporated between the squeezehead and the fill frame and flask.

The table T is supported on the rods 125 and 126 of hydraulic cylinders127 and 128 respectively which extend through the apex of the triangularbase 5. The blind end of each of the piston-cylinder assemblies mayextend into a pit or slight depression 129 in the floor 1.

Referring now to FIG. 4, it will be seen that air operated stops 130 and131 are pivoted to the interior surfaces of the frame legs 12 and 11respectively as shown at 132. and 133. A flask entering the machine inthe direction of the arrow 134 will then engage the distal ends of thestops as shown at 135 and 136 to be in proper position for the loadingoperation. When the flask is to be taken out of the machine,piston-cylinder assemblies 137 and 138 will be caused to extend theirrods 139 and 140 pivoted to the proximal ends of the latches 13d and 131as shown at 141 and 142 respectively, thus to pivot the distal ends ofsuch latches clear of the flask so that it may be removed from themachine in the direction of the arrow. A new flask 145 will be pushedinto the machine and the previously made mold will be ejected. After thenext flask enters the machine, the piston-cylinder assemblies 137 and138 again retract and the stops are positioned to contact the next flask145. On the way into the machine, spring loaded latches 146 and 147 aredepressed by the bottom of the flask and as it clears the latchmechanisms, springs 148 and 149 return them to the slightly elevatedposition shown more clearly in FIG. 2 abutting the end or edge of thebottom flask flange to eliminate the possibility of the flask rollingback out of the machine during the molding cycle. In this manner, theflask will firmly be held between the latches 146 and 147 and the stops130 and 131. Suitable conveyors comprised of rollers similar to thoseshown at 119 may be employed to convey flasks to the machine as at 150and to discharge finished molds as at 151.

Referring now additionally to FIGS. 5, 6 and 7, it will be seen that thesqueeze head 92 employed with the present invention is mounted on thecarriage 91 by means of three I-beams 160, 161 and 162 extendingtransversely thereacross. The I-beams may be secured to the carriage 91by suitable fasteners such as nuts and bolts extending through aperturesin the top flanges of the beams as shown at 163. Similarly, the bottomflanges of the beams may be employed to fasten a head or cavity 164thereto through spacer blocks 165 which may be positioned at oppositeends of each heard. A horizontally extending relatively thick flangemember 166 may be secured as by welding to the lower peripheral edge ofthe cavity member 164. As seen in FIG. 7, the cavity member 164 includestwo side plates 167 and 168 which form, with the cavity member 164having downwardly turned end walls 169 and 176, a downwardly openingcavity which is filled with several layers or blocks of gum rubber. Theillustrated embodiment discloses a total of four such layers fillingsuch cavity and such layers may, for example, be totally 3 /2 inchesthick. The top layer 170 may be /2 inch and the other three layers 171may be 1 inch thick. Aligned openings 172 in such layers lead to atapped extension 173 on the top surface of the cavity member 164 intowhich a coupling 174 is threaded. Two rela tively thick diaphragms 176and 177 are peripherally clamped to the bottom side of the flange orring 166 by a clamping ring 178 of the same peripheral dimension as theflange 166 and the diaphragms 176 and 177. Such clamping ring is heldagainst the diaphragms thus to clamp the same against the flange by aseries of peripherally spaced clamping bolts 179 threaded into theclamping ring 178. It is noted that the interior surface 189 of suchring is slightly outwardly flared and a further ring 181 is secured tothe bottom surface thereof by fasteners such as the screws 182. Thelower ring 181 also has an outwardly flared interior surface 183 whichcooperates with the ring 178 to provide a marginal relatively rigidportion adapted firmly and mechanically to squeeze the periphery of thesand mold, and the interior surfaces and 183 force the sand inwardly tobe squeezed by the downwardly bulging relatively thick diaphragms 1'76and 177. Air at approximately pound per square inch will be supplied tothe back of the downwardly bulging diaphragms through line 185 coupledto the tapped boss 173. It is noted that a similar tapped boss 1&6 isemployed on the opposite side of the head and either or both may beemployed to supply such air under slight pressure to the cavity or space187 behind the diaphragms 176 and 177. In the embodiment shown, theopening in.

the tapped boss 186 may be provided with a plug 188. The layers 170 and171 as well as the diaphragms 176 and 177 may, for example, be naturalgum rubber, polyurethane rubber, or synthetic rubber such as neoprene.The layers 170 and 171, which serve to reduce the fluid volume behindthe diaphragms 176 and 177, may be glued together or otherwise suitablyfastened to provide a resilient block or backup for the space behind thediaphragms, the lowermost layer 171 being tailored to fit the interiorshoulder on the flange 166. The air under slight pressure will cause thediaphragms 176 and 177 to bulge downwardly as shown. However, during thesqueeze operation when it is acting on the sand under pressure, it willtend to flatten out and in high spots of the mold, it will contact anddepress the layers 170 and 171. During the molding operation, thepressure provided by the hydraulic cylinders 127 and 128 will raise thetrapped pound per square inch pressure behind the diaphragm to over 100pounds per square inch thus giving a uniformly hard mold, the back ofwhich will be contoured to the sand and pattern resistance that thediaphragm meets. It can then be seen that with a 30 x 38 x flask that atotal of over 100,000 pounds pressure will be exerted behind thediaphragm.

Operation of the FIG. 1 embodiment Referring now more particularly toFIG. 8, it will be seen that the pneumatic components of the machine areoperated by a series of four way solenoid power operated valves havingmanual overrides. The valve 200 operated by solenoid 201 is effectivethrough /2 inch hose lines 202 and 203, for example, to control theoperation of the cutoff slide piston-cylinder assemblies 45 and 46.Similarly, valve 204 operated by solenoid 205 is effective through 1inch hose lines 206 and 207 to operate the piston-cylinder assembly 87to position the carriage which includes the squeeze head 92 and chute 96to either squeeze position or fill position. Also, the valve 208operated by solenoid 209 is effective through lines 210 and 211 which,like the lines 202 and 203, may be /2 inch hose lines to control theoperation of piston-cylinder assembly 68 either to open or close thelouvers 75. Flow control units 212 comprised of a variable restrictionvalve and a check valve in parallel may be provided in each of the linesleading to the piston-cylinder assemblies 45, 46, 68 and 87.

A valve 214 operated by solenoid 215 is effective to supply air underpressure selectively during the cycle of the machine through pipes 216to a pattern blow-cit, and similarly a valve 217 operated by solenoid218 is effective to supply air through lines 219 to a pattern sprayunit, not shown. Air for the valves 200, 204, 208, 214 and 217 issupplied from a source 220 through an air line filter 221 which leads tosupply line 222. A radial flow exhaust mufller 223 may be provided inexhaut line 224. A branch 225 in the supply line leads to the pairs ofupset frame hold-down piston-cylinder assemblies 114 and 115. Such upsetcylinders may be provided with a 2 /2 inch bore and a 14 inch strokewith cushioning at the blind end only.

Hydraulic fluid under pressure may be supplied alternately to the lines227 and 228 or the line 229 from a hydraulic power unit, respectively toraise and lower the table T through the piston-cylinder assemblies 127and 128. The hydraulic power unit which may, for example, be onecommercially sold by Brown & Sharpe will have a pressure responsivedevice so that when the desired pressure is obtained, the pressure willbe switched from lines 227 and 228 to line 229. As the table with theflask supported therein descends and as the flask approaches the rollers110, the downward speed of the table will be slowed or reduced so thatthe drawing of the pattern from the produced sand molds will be at arelatively low speed. The table may be provided with a bracket 231having a cam 232 thereon adapted to operate a vibrator valve 233supplied through line 234 which leads through valve 200 so that thevibrator will be operative only when the cutoff plates 35 and 36 areclosed and when the valve 233 is open governed by the position of thetable T. The vibrator may be employed to assist in the compaction of thesand within the flask and/or to facilitate the drawing operation.

Air may be supplied to a pressure regulating valve 236 which willincrease the pressure in line 237 until a diaphragm type unloading valve238 unloads, such valve being set to unload at 1 pound per square inch.When the valve 238 relieves, the setting of the valve 236 can be reducedone turn so that the pressure supplied through check valve 239 throughline 185 to the chamber 187 behind the diaphragm will remain somewhatless than 1 pound per square inch or A of a pound per square inch.

The latch operating piston-cylinder assemblies 137 and 138 may beoperated, for example, through lines 240 and 241 with a flow controlunit 242 being provided in the line 240 leading to the blind end of thepiston-cylinder assembly 137. The air supply in such lines can becontrolled by suitable solenoid operated valves signalling the conditionof the machine at the completion of the cycle so that the flask F can becleared for movement from the machine.

With the machine shown in the position of FIG. 1, the first operation isto shuttle the squeeze head out from under the measuring box 60 with thecarriage pneumatic piston-cylinder assembly 87. At the same time, thehydraulic squeeze pistons 127 and 128 will raise the table with thepattern and plate P positioned thereon lifting the flask F from therollers until the flask contacts the upset frame 118. When the flask andupset are in contact, the table stops rising and the louvers of the sandbox are opened by the piston-cylinder assembly 68 for the desired lengthof time. Since the upper cutoff slides 35 and 36 are closed whenever thelouvers 75 are opened, only the amount of sand, which is determined bythe height of the louver assembly 63, within the measuring box 60 isdropped into the flask. The sand will drop through the chute 96 whichhas been placed in alignment between the measuring box 60 and the flaskF. Before the table again begins to move upwardly, the squeeze head andchute will be shuttled to the position shown in FIG. 1 by the extensionof the piston-cylinder assembly 87 The movement of the chute will causethe excess sand within the flask and fill frame to be struck off. Whenin the position shown, the table will start to move upwardly and thelive air on the rod end of the pairs of cylinders 114 and 115 holdingthe fill frame down will be compressed and forced back into the supplyline 225. Continued upward movement of the table causes the sand withinthe flask and fill frame to be compressed to a hardness which is afunction of the hydraulic pressure in the squeeze cylinders 127 and 128.When the desired pressure is obtained, the cycle is reversed and theflask and fill frame will start to lower away from the head with thelive air which is kept on the rod end of the pairs of cylinders 114 and115 keeping the upset on top of the flask as it is lowered. As the flaskapproaches the rollers 110, the downward speed of the table T is reducedto slow the drawing operation and continued downward movement of thetable will draw the pattern from the sand mold. The latchingpiston-cylinder assemblies 137 and 138 will then be actuated to clearthe flask for discharge from the machine and a new flask will bepositioned in its place so that the above-described cycle may berepeated.

The FIG. 9 embodiment Referring now particularly to FIGS. 9 and 10,there is illustrated a machine similar to the above-described machineusing a modified form of squeeze head. The machine is mounted on a base250 of the similar triangular configuration as the base 5 shown in FIG.1 and four upstanding legs 251 support the major components of themachine. The legs 251 support on the tops thereof an auxiliary frame inthe form of a small stand 252 which in turn supports the hopper 253 forthe sand mix. Two piston-cylinder assemblies 254 and 255 on each side ofthe hopper 253 are employed to operate the cutoff slides 256 and 257 bywhich the sand mix is selectively dumped into the sand measuring box258. Louvers 260, operated by piston-cylinder assemblies 261 and 262,open to drop the load of sand therein through chute 263 when the slides256 and 257 are closed, or close to maintain the proper amount of sandtherein when the slides 25-6 and 257 are opened. The squeeze head showngenerally at 264 is connected with the chute 263 by means of a link 265and both are shuttled horizontally back and forth by the piston-cylinderassembly 266. The rod 267 of such piston-cylinder assembly is connectedto the carriage of the squeeze head as shown at 268. The bottom of thechute 263 may be in the form of a cloth curtain or the like and both thesqueeze head and chute are supported on side flanges which ride oninwardly directed rows of rollers 269 and 270. Hold-down bars 271 and272 supported by brackets 273 and 274 extending downwardly fromtransverse frame members 275 and 276 serve to overlie and confine thesupporting flanges 277 and 273 of the squeeze head 264 in the squeezeposition.

A fill frame 280 is supported on brackets 281 and 232 secured to thelegs 251 of the machine frame. Guide pins 283 extend through suchbrackets to guide the fill frame for vertical movement. A flask F isbrought into the machine on rows of rollers 284 and 285 mounted onroller bars 236 and 287 respectively.

The table T is supported for movement on the rods 2% and 291 ofpiston-cylinder assemblies 292 and 293. Flexible boots 2% and 295 may beemployed to protect the exposed rods extending from such cylinders. Apattern and pattern plate P will be supported on the top of the table Tin the same manner as in the FIG. 1 embodiment.

The operation of the machine will be substantially identical to that ofthe FIG. 1 embodiment wherein the flask is moved into the machine and isengaged by the pattern and plate supported on the table T as the same iselevated. The elevation of the flask and table causes the flask toengage the upset frame 280 to move the same upwardly. However, after themold box has been formed by the table, flask and fill frame, thepiston-cylinder assembly 266 will cause the carriage to shuttle to theposition shown in FIG. 9 wherein the squeeze head 264 will be positionedto overlie the thus formed mold box after it has been filled with sandfrom the measuring box falling through the chute 263. When the squeezehead is in the proper position, the side marginal edges thereof willunderlie the members 271 and 272 to provide a top support therefor andcontinued upward movement of the table with the mold box formed thereonwill cause the sand within the mold box to engage the squeeze head 264compressing the sand to the desired hardness. At the completion of thesand squeezing operation, the table will start downwardly separating thecomponents of the mold box and drawing the pattern from the sand moldformed within the flask.

The squeeze head employed with the machine of FIG. 9 is comprised of amultiplicity of downwardly projecting piston-cylinder assemblies 3%which are supported on the squeeze head carriage for horizontalshuttling into and out of operative squeeze position.

Referring now to FIG. 11, there is shown one form of piston-cylinderassembly that may be employed with the piston-cylinder squeeze head ofthe present invention. The squeeze head carriage may be provided withtop and bottom support plates 301 and 302 spaced by collars 333 whichmay be welded to the plate 301 and held together by nut and boltassemblies 304. An annular seal 305 may be positioned between the endface of the collar 303 and the plate 302. Stationary piston rods 3% maybe inserted in aligned apertures 307 and 303 in the plates 301 and 392respectively and a snap ring 369 may be employed cooperating withshoulder 310 to hold the rod in proper position. A dowel pin 311 or thelike may be employed to lock the rod in its proper rotative position.The rod is provided with two vertically extending passageways 312 and313 with both having tapped enlargements 314 and 315. The transversepassageway 316 connects the passageway 312 with the interior space 317between the plates 301 and 362. A plug may be positioned in the tappedenlargement 314 and the enlargement 315 may be coupled to a vent or thelike. Seals 318 and 319 may be provided to seal the interior 317. Thelower end of the rod is provided with an enlarged portion 320 whichserves as the piston for cylinder 321. Sliding seals 322 and 323 sealthe piston against the inside of the cylinder. Passageway 312 isprovided with a bottom enlarged portion 324 which accommodates a guiderod and oil tube 325 which is secured to a plug member 326 which issealed as shown at 327 and held to the outer end of the cylinder 321 bya snap ring or the like 328. A square bottom shoe 329 is held to themember 326 by screws or the like 3311 so that the tube 325, member 326and shoe 329 are all firmly rigidly mounted on the outer end of thecylinder 32]..

Snap rings 331 and 332 are employed to hold annular member 333 in theopposite end of the cylinder and additionally the snap ring 332 holds awiper 334 adapted to wipe over and clean the exterior 335 of the rod306. A sliding seal 337 may be employed to maintain the vent end of thecylinder in the proper sealed condition and also a seal 338 similar tothe seal 327 may be employed.

It is noted that the hollow rod 325 is oil-center from the center of thecylinder 321 and accordingly relative rotation of the piston andcylinder is precluded. Since the square shoes 329 will be relativelyclosely juxtaposed over the entire bottom surface of the squeeze head,such rotation could result in interference between the shoes and damageto barred flasks, sprues, gates, etc. It can now be seen that the plates331 and 302 can be spaced and sealed to act as a manifold for the oil orfluid pressure acting upon the piston-cylinder assemblies.

In FIG. 12 there is illustrated a slightly modified form ofpiston-cylinder squeeze head wherein plates 34% and 341 are heldtogether by screws 342 or the like with such screws also being employedto hold cylinders 343 in the proper sealed relationship to the bottom ofplate 341. Apertures 344 in the plate 341 are aligned with manifoldingpassages 345 in the plate 346 so that each of the cylinders will beconnected to the same source of fluid under pressure. The rod ends ofthe cylinders may be closed by plates 346 held thereto by screws 347 andsuitable wipers 34 8 may be employed to wipe the shank of rod 349 topreclude excessive wear from sand clinging thereto. The sealing member350 may be held to the piston 351 by the cap 352 threaded on stud 353and held thereto by a lock nut or the like. It is noted that the shankof the rod 349 extends through the aperture 354 in the plate 346eccentrically of the piston rod 353 and this precludes relative rotationof the piston and cylinder. Square shoes 355 or the like may be fastenedto the ends of the rods by screws 356 and as seen, the juxtaposed shoe357 is fairly close and thus relative rotation would cause interferencebetween adjacent shoes, since it will be realized that the shoes may beat different heights during the squeezing operation. Lubricant fittings358 may be employed properly to lubricate the piston and cylinder.

Referring now to FIG. 13, it will be seen that the pistoncylinderassemblies 3% can be supplied with a source of hydraulic fluid underpressure from a reservoir 360 and air may be supplied to such reservoirthrough the line 351 to force the hydraulic fluid outwardly through line362. A check. valve 363 in parallel with a hydraulically operated cutoffvalve 364 supplies such hydraulic fluid to the manifold 365 connected toall of the piston-cylinder assemblies. As the hydraulic pistons 292 and293 elevate the table to form the mold box and to squeeze the sandtherein against the piston-cylinder assemblies 300, the pressure willbuild up in the lines 366 causing the valve 364 to shift locking thefluid within the piston-cylinder assemblies and fixing it as toquantity. Thereafter, the piston-cylinder assemblies can move relativeto each other but for every upward movement of one, there has to be anequalizing downward movement of another or others. A variablerestriction valve 367 may be provided in series with the hydrauliccutoff valve 364. The vent lines to the various cylinders may passthrough an air filter 368 to atmosphere. The hydraulic cylinders 292 and293 may be supplied with hydraulic fluid from a reservoir 369 throughfilter 370 and pump 371 driven by motor 372. Such is a conventionalhydraulic power supply unit.

It can now be seen that intially each of the pistoncylinder assembliesmay retract simultaneously due to the force of the sand thereagainstcompressing the air source, but as the pressure builds up within line366, the hydraulic cutoff valve 364 will operate fixing the fluid behindsuch piston-cylinder assemblies as to quantity. Thereafter, relativemovement of the piston-cylinder assemblies may be obtained so that eachshoe thereof will conform generally to the surface of the pattern, butfurther total movement or retreat is precluded.

By way of further explanation, with reference to FIG. 13, it can be seenthat the valve 364 is shown schematically as a sliding spool type havinga blocking position 375 and an open position 376 which can be registeredwith line 377 to close and open the same, respectively. Movement of thespool or valve element is afforded by pressure in pilot line 366connected to the line 377 at 378 urging the valve against the pressureof spring 379 to shift the same from its open to its blocking position.It can now be seen that the variable restriction valve 367 is in serieswith the blocking valve 364 in line 377. Thus the valve 364 functions toopen or close line 377 depending upon the pressure in line 366. Afterthe mold has been squeezed, and the table T is lowered from the head,the spring 379 on one end of the valve element will overcome thepressure exerted by the fluid in pilot line 366 permitting the valve toreturn to its open position providing communication therethrough betweenthe manifold and the reservoir 360.

It can now be seen that there is provided foundry molding machines whichwill very rapidly produce foundry sand molds of uniform high surfacehardness having squeeze heads capable of withstanding high pressures andconstant uses, such squeeze heads conforming to the requisite of thepattern, barred flasks, gates, sprues or the like depending upon theparticular arrangement desired. For example, it has been calculated thatthe hydraulic cycle time of the machine need only be 6.6 seconds withthe approach taking 2.3 seconds, the squeeze taking 1.5, and the draw2.8. Rugged squeeze heads providing an equalizing pressure on the entireupper surface of the molds thus rapidly produced are disclosed which canadditionally take the continual horizontal reciprocating movementsrequired in the gravity fill machines illustrated.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

We, therefore, particularly point out and distinctly claim as ourinvention:

1. A squeeze head for foundry molding machines comprising aseries ofdownwardly projecting piston-cylinder assemblies, means manifolding eachof said piston-cylinder assemblies to a common source of fluid underpressure, and means responsive to a predetermined pressure in saidmanifold means operative to fix the quantity of fluid in said system.

2. A squeeze head as set forth in claim 1 wherein said piston-cylinderassemblies comprise downwardly extending fixed rods, cylinder meansmovable on said rods, and squeeze biscuits on the bottoms of saidcylinder means, said downwardly extending fixed rod means having avertically extending passageway therein, and a guide rod extendingupwardly from said squeeze biscuit being guided in said downwardlyopening passage and offcenter from said cylinder means to keep saidcylinder from rotating with respect to said rod means.

3. A squeeze head as set forth in claim 1 wherein said piston-cylinderassemblies comprise downwardly extending fixed cylinder means, pistonand rod means extending downwardly from said cylinder means and havingsqueeze biscuits mounted on the ends thereof, said rod means beingeccentric with respect to said cylinder means to keep said piston androd means from rotating with respect to said cylinder means.

4. A squeeze head for foundry molding machines comprising a plurality ofprojecting sand engaging piston cylinder assemblies, means manifoldingeach of said piston-cylinder assemblies to each other and to a commonsource of fluid under pressure, means responsive to a low squeezepressure of said assemblies against such sand operative to decrease thevolume of fluid in said assemblies as the latter retreat against thepressure of such sand, and means responsive to an increased squeezepressure against such sand to fix the quantity of fluid in saidassemblies while nevertheless permitting relative adjustment of saidassemblies.

5. A foundry molding machine comprising a squeeze head, a tablevertically movable therebeneath and adapted to support a patterncontaining sand filled flask, said squeeze head comprising a series ofdownwardly projecting squeeze members, pressure chambers acting on eachof said members, means manifolding each of said chambers to a commonsource of fluid under pressure, said members being adapted to retreatagainst the pressure in the respective chambers as said table iselevated to bring such sand filled flask against said squeeze head, andmeans responsive to a predetermined pressure in said manifold means tofix the quantity of fluid therein.

References Cited by the Examiner UNITED STATES PATENTS 364,948 6/1887Moore 22-41 1,944,168 1/1934 Camerota 22-65 2,341,012 2/1944 Billman etal 25-41 2,686,345 8/1954 Ypung 22-35 2,850,775 9/1958 Northington et al22-20 2,852,820 9/1958 Taccone 22-40 2,956,316 10/ 1960 Deakins et a122-20 2,959,828 11/1960 Frankenstein 22-45 2,968,846 1/1961 Miller 22-363,041,685 7/1962 TaCCOne 22-42 3,049,988 4/1962 Lindemann et a1. -2373,089,207 5/1963 Miller 22-10 MARCUS U. LYONS, Primary Examiner.

MICHAEL V. BRINDISI, Examiner.

1. A SQUEEZE HEAD FOR FOUNDRY MOLDING MACHINES COMPRISING A SERIES OFDOWNWARDLY PROJECTING PISTON-CYLINDER ASSEMBLIES, MEANS MANIFOLDING EACHOF SAID PISTON-CYLINDER ASSEMBLIES TO A COMMON SOURCE OF FLUID UNDERPRESSURE, AND MEANS RESPONSIVE TO A PREETERMINED PRESSURE IN SAIDMANIFOLD MEANS OPERATIVE TO FIX THE QUANTITY OF FLUID IN SAID SYSTEM.